Boats running in shallow, rocky water conditions can sustain major damage on impact with underwater obstacles. To avoid damaging the hull, various techniques have been attempted, including application or attachment of a coating or a protective plate. None have been satisfactory.
Prior designs contemplate attaching plastic directly to the bottom of the hull using different methods. Some drill tapered holes in the plastic then weld in tapered aluminum washers to the aluminum hull. Some glue or glue and vacuum plastic to the hull. More common is to bolt the plastic through the hull every few inches. In some cases, drilling through the hull and bolting, sometimes drilling through and taping, into the aluminum hull. These various ideas to secure the plastic directly to the hull make a slippery surface if the bat comes in contact with the river bottom, but have many drawbacks, including:                1. Drilling lots of holes in the hull can lead to leaks as the bottom hits and slides on rocks, it can loosen and bend the attaching bolts, which can result in leaks and the plastic separating from the boat bottom;        2. When the plastic is attached in so many spots, it tends to buckle and wave when it changes temperature and the boat performance is reduced due to a deformed running surface;        3. Gluing is a problem as the plastic expands at a different rate than the boat hull in different temperatures and tends to break free; and        4. The main problem is that when a large rock is hit and the plastic is attached directly to the hull, the hull will receive the impact and be damaged.        
Therefore, there is a need for a hull shield to avoid the aforementioned disadvantages.